Micellar Thin Layer Chromatography and Computer-Aided Analysis of Empagliflozin, Linagliptin and Metformin HCl Ternary Mixture.

The present work was performed in order to study the mechanism of micellar thin layer chromatography (MTLC) and to develop a new simple and sensitive simultaneous MTLC method for separation of empagliflozin, Linagliptin and metformin hydrochloride ternary mixture. The study was done using three different surfactants; sodium dodecyl sulphate (SDS), benzalkonium chloride (BAC) and polysorbate 80 (tween 80). Chromatographic procedure was performed using micellar mobile phase that composed of aqueous solution of each surfactant and methanol (6: 4 v/v) and micellar TLC determination at λmax 237 nm. Separation using SDS (anionic surfactant) and BAC (cationic surfactant) depends on ionization potential (AMI-IP), partition coefficient (logP (o/w)) and hydrogen bond donor atoms (a-don), whereas separation using tween 80 depends mainly on the lipophilicity (RM0), solvation energy (E-sol) and Van der Waals energy (E-vdw). Quantitative structure-retention relationships study was carried out, modeled, evaluated and validated using molecular operating environment software.

Simple TLC-spectrodensitometric method for studying lipophilicity and quantitative analysis of hypoglycemic drugs in their binary mixture.

A selective and simple salting-out-assisted thin-layer chromatographic methodology was developed for the simultaneous determination of two oral hypoglycemic drugs, dapagliflozin (DAPA) and metformin (MET) in their pure forms, tablets and spiked human plasma samples. Silica gel 60 F254 plates were used in the separation of the two drugs using a mobile phase consisting of 0.5 m (NH4 )2 SO4 and methanol (3:7, v/v). The plates were scanned in the reflectance mode at λmax = 237 nm. The obtained retardation factor (Rf ) values for DAPA and MET were 0.77 ± 0.02 and 0.25 ± 0.02, respectively. The thin-layer chromatography method was validated according to International Conference on Harmonization guidelines. The peak areas were linearly increased with the increases in concentrations of 45-1,000 and 50-1,500 ng/band for DAPA and MET, respectively. Moreover, the method was applied to estimate the molecular lipophilicity parameters of DAPA and MET via retention data. The suggested method was efficiently utilized for the analysis of DAPA and MET in pharmaceutical tablets and plasma samples with recoveries 98.4-100.4 and RSDs in the ranges of 1.4-2.6 and 2.2-3.0% for DAPA and MET, respectively.

Factorial approach for the optimization and development of stability indicating study of the contraceptive suspension for injection(Depo-Provera®).

The study involves use of factorial design for optimization of forced degradation conditions and development of stability indicating method for medroxyprogestrone acetate (MPA) or depo-provera as known in the market. MPA is an important contraceptive and anticancer drug especially for treatment of breast cancer and it is the first time to study the different conditions affecting its stability. MPA was subjected to different variables such as solvent type, pH and the time subjected to UV light. Factorial design has been used during forced degradation to determine significant factors responsible for degradation and to optimize degradation conditions reaching maximum degradation. Factors responsible for forced degradation were statistically evaluated using Bubble and Surface plots. Variables proved to be significant (p < 0.05) and the suggested model represented a perfect example for indicating the efficiency of factorial designs in optimizing the degradation conditions that give maximum percent of degradation. We investigated also the solubility and stability profiles of MPA in aqueous solutions. Stability study results showed a very low stability profile of MPA in all the aqueous solutions with rapid degradation rate more than other solvents. The current research may contribute to enrich the knowledge of the physicochemical properties of this drug for exploring its full anticancer potential in the future.

TLC-spectrodensitometric method for simultaneous determination of dapagliflozin and rosuvastatin in rabbit plasma: stability indicating assay and kinetic studies.

Herein, a sensitive and reliable eco-friendly TLC-spectrodensitometric method has been established for the simultaneous determination of dapagliflozin (DAPA) and rosuvastatin (ROSV) for the first time. TLC separation was carried out on silica gel F254 using ethyl acetate : methanol (5 : 0.1, v/v) as a mobile phase and UV measurement at 243 nm. The method was fully validated according to ICH guidelines. Acceptable separation was achieved with R f values of 0.23 and 0.44 for DAPA and ROSV, respectively. Regression plots revealed linear relationships in the concentration range 20-2500 ng per band and 10-2500 ng per band with LODs of 6.60 and 3.57 ng per band for both DAPA and ROSV, respectively. The relative standard deviations (RSDs%) were found to be 1.35 and 0.53 for DAPA and ROSV, respectively. Moreover, kinetic studies were conducted for measurement of degradation rate constant (k) and half life time (t 1/2) of DAPA and ROSV via forced photo-degradation.

Simultaneous TLC-densitometric determination of tamoxifen citrate and medroxyprogesterone acetate and UV-degradation kinetic study of medroxyprogesterone acetate.

Coadministration of tamoxifen citrate (TMC) and medroxyprogesterone acetate (MPA) is preferred to increase the response rate and the percentage recovery in patients with endometrial carcinoma. Administration of TMC and MPA and their combination affects estrogen and progestin receptor concentrations in advanced endometrium carcinoma by affecting 17ß-hydroxyl steroid dehydrogenase activity and serum hormone concentrations. A sensitive, accurate and robust thin-layer chromatography method has been established for simultaneous analysis of TMC and MPA. Method development was carried out on silica gel F254 using butanol-acetic acid-water (6:0.5:0.5, v/v/v) as mobile phase. Densitometric scanning was carried out at 241 nm for simultaneous detection of TMC and MPA. Retardation factor (Rf ) values for TMC and MPA were 0.21 and 0.85, respectively. The method was validated according to ICH guidelines. Regression plots revealed linear relationships in the concentration range of 50-500 and 25-250 ng/band for TMC and MPA, successively. Accuracy was ≥99.60 and 98.72% for TMC and MPA, respectively. Forced degradation studies using UV photodegradation was applied on MPA after exposure to UV light for different times and applying a kinetic study for calculating the degradation rate constant (k) and half-life time (t1/2 ).